BROWN v. WALLACE. 603

bill to stay waste or proceedings at law, to be filed before the sub-
paena is issued, (w)

Under our government, the federal courts and the state courts
have, in many instances, a concurrent jurisdiction; and either may
have cognizance of the case, either as a court of common law or
of equity. If the plaintiff and the defendant be citizens of different
states, the suit may be brought in either; but if the suit be insti-
tuted in a state court, its proceedings will not be stayed by an
injunction from a federal court; or the reverse; not because the
court has not jurisdiction of such a subject between those parties;
but because it could not exercise its jurisdiction in that case, with-
out bringing itself injuriously in conflict with another tribunal,
with whom it ought not on any account to interfere, (x)

The two great co-ordinate courts of equity of England, are the
High Court of Chancery, and the Court of Exchequer. The first
is the prototype of this court. The Exchequer, as the phrase is,
has two sides; it is a court of common law, as well as of equity.
It is composed of a plurality of judges; and is, in all respects, a
term court; being in these particulars, essentially different from
the Court of Chancery; which is composed of only one judge, and
is most emphatically, always open. The Exchequer, like our fede-
ral circuit courts, and our state county courts, is so organized, that
it can exercise scarcely any of its equity powers, except in term
time; and owing to the delays and expense of proceeding with its
equity business only from term to term, the continually open Chan-
cery Court, has a most decided advantage over the Exchequer,
which, on that account, is almost deserted as a court of equity, (y)

In this, and other respects, the analogy between the High Court
of Chancery, and the Court of Exchequer of England, as co-ordi-
nate courts of equity, and the High Court of Chancery, and the
county courts of equity of Maryland, as co-ordinate courts of the
same description, is so close and striking, that the cases in relation
to the conflicts of jurisdiction, between those English courts, may
be applied as most instructive illustrations of the effects of any
similar clashing between our own co-ordinate courts of equity.

It is a rule between those English courts, that where they have
both an entirely concurrent jurisdiction of the same matter, that

(ID) Williams v. Hall, 1 Bland, 193, note.—(x) Diggs v. Wolcott, 4 Cran. 179;
McKim v. Voorhies, 7 Cran. 279.—(y) Crowley's Case, 2 Swan. 11; 1 London
Jurist, art. 7.